Internal-combustion engine



Dec. 4, 1934. c EDWARDS 1,983,351

INTERNAL COMBUST I ON ENGINE Filed Aug. 10, 1952 gwuc/fvto'b 173555???"E EDA/HERE.

Patented Dec, 4, 193

1,983,351 INTERNAL-COMBUSTION ENGINE Herbert 0. Edwards, Detroit, Michassignor to Packard Motor Car Company, Detroit, Mich a corporation ofMichigan Application August 10, 1932, Serial No. 628,216 12 Claims. (Cl.123-32) This invention relates. to engines and more particularly tointernal combustion engines.

The main object of the present invention resides in the association withan internal com- 9 bustion engine of means for stabilizing its speed ofoperation during idling.

Another object of the invention is to provide an engine in whichnegative work is introduced into the cycle in order to stabilize idlingspeed. A further object of the invention is to provide an internalcombustion engine with means for relieving the explosion chamber duringthe working stroke in order to introduce negative work and therebystabilize the engine when idling.

Other objects of the invention will appear from wthe followingdescription taken-in connection with ithe'drawing', which forms a partof this specifi= cation, and in which:

lig. 1 is a vertical sectional view of an engine having stabilizingmechanism, forming the subject of this invention, associated therewith;

Fig. 2 is a fragmentary sectional view of the engine with thestabilizing mechanism in a po- 25 sition to permit pressure relief;

Referring now to the drawing by characters of reference, 10 representsthe crank case of an internal combustion engine having one or morecylinders as indicated at 11 associated therewith. The usual crank shaft12 is carried within the crank case and connected thereto is a rod 13which is also connected to the piston 14 arranged to reciprocate withinthe cylinder. The engine illustrated is of the two-cycle type and hasprovision for separate introduction of air and atomired liquid fuelwhich unite to form fuel charges which ignite by means of heat developedby compression in the cylinder. It will be understood, however, thatthis invention can be applied to four or other cycle engines.

Suitable sets of ports, as indicated at 1.5, are provided through thecylinder walls in diametrically opposite relation and one set of suchports act as air inlets and the other set of ports act as exhaustoutlets in the conventional two-cycle manner. The piston is alsoprovided with a flanged head portion 16 which is associated to cooperatewith the set of air inlet ports in a manner to direct air upwardly inthe cylinder when first admitted therein.

Suitable mechanism is associated with the engine for injecting variablecharges of liquid fuel into the cylinder. In this instance, there is anozzle 1'7 anda pump 18 which are secured together to form a unitarystructure. A portion 86 of the nozzle extends through the cylinder walland associated with the outlet end thereof is a valve 19 which isnormally substantially closed. Associated with the pump unit is aplunger 9 which is reciprccated by articulated push rod 69 members 20and 21. The plunger controls passages, as indicated at 22, to trapliquid fuel and, after closing such passages, the plunger creates apressure against the trapped fuel sumcient to open the valve 19whereupon the fuel charge 65 is sprayed into compressed air in thecylinder.

A cam 23, driven from the crank shaft, is arranged within the crank caseand associated therewith is a rock lever 24' which is mounted on a shaft25. This rock lever has a curved face iii 26 upon which the push rodelement 21 can be adjusted in a direction to change the eifective strokeof the plunger. An arm 27 is fixed to the shaft 28 upon which is alsofixed a hand lever 29 and cbnnecting the arm with the link 21 is iiianother link 30. By rocking the shaft 22, through means of the lever 29,the arm 27 and link 30 can be moved to adjust the rod element 21 alongthe curved face 26 of the rock lever and thus the quantity in the fuelcharges delivered so from the injection device can be varied. When therod 21 has been adjusted to the position shown in dotted lines in Fig.i, then the plunger will no longer cover the ports 22 during itsreciprocation and consequently no fuel will be delivered into the 35cylinder. The position of the rod 21' on the curved face 26 willdetermine the distance the plunger moves past the ports 22 and will thusregulate the quantity of liquid in the fuel charges delivered from theinjection device. This fuel an injection device does not form a part ofthis invention and for a betterunderstanding thereof reference can behad to application Serial No. 358,899 filed by Lionel M; Woolson, April29, 1929 and issued February 7, 1933 as Patent No. ,95

With the engine described, air is admitted into the cylinder and istrapped therein by the piston and compressed, and during the compressionstroke, the fuel injection mechanism is timed to ma project charges ofatomized. liquid fuei into the air charges in the cylinder whereupon themixture of air and fuel will be ignited through the heat of compression.The explosion of the mixture moves the piston away from top center ofthe cylinder until it uncovers the set of outlet ports whereupon anothercharge of air rushes into the cylinder, through the set of inlet ports,displacing the exhaust gases and filling the cylinder with air. I havefound with engines of the compression-ignition type that the adjustmentof the injection device to regulate the fuel volume is very unstablewhen set for idling of the engine due to the high pressure and minutevolume dispensed, and consequently if continued ignition is to bemaintained, then the injection device must be set to deliver a greatervolume of fuel than is required and, as a consequence, the engine speedis maintained higher than is desirable for some purposes and foreconomy. When an engine of this type is utilized as the power plant ofan aeroplane, it is essential that there be no stalling during idlingbecause the engine must be idling when landing, but with the fuel volumeadjustment regulated to insure that there will be no stalling duringgliding of the aeroplane, the speed developed is too high for safelanding.

The purpose of this invention is to associate with an engine of the typedescribed, means whereby negative work is introduced in the cycle whenidling to permit adjustment of the injection device sufficient to insurecontinued ignition and, at the same' time, reduce the engine speed overthat which would normally result with such a fuel delivery.

In order to provide for such stabilizing of an engine of the characterabove set forth when idling, I propose to associate with the cylindermeans for relieving it of some of the gaseous con- .having a neck 32with a passage therein which opens into the interior of the cylinder.The passage communicates with the chamber 33 in the housing and fromwhich extends an outlet neck 34 having a passage therein leadingexteriorly of the cylinder. The housing is formed with another neck 85which is formed hollow to provide a. bearing for valve 36 whichco-operates with a seat 37 formed at the junction of the passage in theneck-32 with the chamber 33. 4

Suitable mechanism can be associated with the valve to control itsrelation with the seat and thereby regulate the escape of gas from thecylinde'r. Preferably I propose that such mechanism be associated withthe fuel control lever so that the valve regulation will occurautomatically and in a predetermined relation with the adjustment of thefuel charges so that the valve can open during idling operation of theengine and be positively closed when the engine is operating at a speedabove idling. To this end, a regulating member 38 is mounted toreciprocate within the neck 35 of the housing and is provided with anopen end into which the valve stem end extends so that in this respectthe member also serves as a guide for the valve. Intermediate theregulating member 38 and the bearing portion 39 of the valve is a coilspring 8 which exerts sufficient pressure to normally close the valve,and contacting with the end of the control member is a cam lever 40which is pivotally mounted upon a pin 41 carried by extended earportions of the neck, as indicated at 42. This cam lever contacts withthe regulating element 38 and carries a roller 43 which is engaged by acontrol member 44 which is pivoted as at 45 to an ear 46 projecting fromthe housing. Pivotally connected to the control member and the handlever is a rod 4'7. The control member is provided with a curved face48, the radius of which is taken'on the pivotal point of the member, andwith a straight face 49 which extends substantially at right angles tothe curved face. The faces 48 and 49 provide contact surfaces forengaging the roller 43 and controlling the position of the valveregulating member.

When the roller is in contact with thecurved face 48, the cam lever 40will be maintained in a substantially uniform position pressing thecontrol member 38 in a direction towards the valve head and therebycompressing the spring to such a degree that the valve will be heldpositively seated irrespective of the pressure developed in the cylindertending to open the same. When the regulating member 44 is moved so thatthe face 49 engages the roller 43, the cam member can be rocked by thespring in a direction such that spring pressure is relieved and when thepressure in the cylinder overcomes such spring pressure, then there wiilbe escape of gas from the cylinder through the chamber 33 and the outletpassage 34.

With the mechanism in the position illustrated in Fig. 1, the fuelinjection device is adjusted-$0 a closed position against the seat 37.Asian as' the roller contacts with the curved face 48, the valve will beheld in this position and this face is of such length that when the fueladjustment is regulated so that the volume of the charges results in anengine speed above idling, the valve will be held closed. When the lever29 is moved in the lower portion of its range to produce an idlingcondition of the engine by reducingthe volume of the fuel chargesdelivered, then the control member will be rocked to a position as"shown in Fig. 2 wherein the roller 43 will engage the face 49 and, undersuch circumstances, compression of the spring is relieved and the valvecan be opened by the pressure of expanding gas in the cylinder andpreferably during the begin 1 can be calibrated or designed to meet anyre- 1 quired pressure conditions. Upon release of gas from the cylinderduring the working stroke, negative work is introduced into the cycle.In other words, expansion pressure in the cylinder drops belowatmospheric pressure causing the piston to do more work and thus 1slowing down the speed of the engine so that the volume of the fuelcharges can be maintained higher than if the relief valve were notemployed. This greater fuel volume gives more assurance that the fuelcharges will be of a uniform nature so that the engine will not stallwhen idling and, at the same time, maintains the engine speed constant.As a. result, idling speed of the engine is stabilized because theinjection device is more;

eficient and also, the engine will be governed so that a uniform idlingspeed is maintained.

Although the invention has been described in connection with a specificembodiment, the principles involved are susceptible of numerous otherapplications which will readily occur to persons skilled inthe art. Theinvention is therefore to be limited only as indicated by the scope ofthe appended claims.

What I claim is:

1. The method of operating an engine comprising introducing air andliquid fuel into a combustion chamber, compressing the air and fuelmixture until combustion occurs, introducing negative work in theexpansion portion of the cycle only when the engine is idling throughthe release of gas from the cylinder, and scavenging the exhaust gasfrom the cylinder.

2. The method of operating an engine comprising introducing unthrottledair charges and charges of liquid fuel into a cylinder, compressing theair and fuel mixture until combustion occurs, automatically introducingnegative work. into the cycle in the work performing period thereof onlywhen operating under engine idling conditions, and scavenging exhaustgases from the cylinder.

3. In an internal combustion engine, the combination with a workingcylinder, of stabilizing means comprising a cylinder relief passage, avalve in said passage, spring means associated to normally seat thevalve when the pressure thereof is greater than the pressure in thecylinder, means for securing said valve in closed position, and fuelcontrol mechanism connected to regulate said means.

4. In an engine of the fuel injection type, the combination with acylinder, of an adjustable pressure relief means, a fuel controlmechanism, and connection means between the relief means and the fuelcontrol mechanism, the adjustment of said mechanism adjusting saidpressure relief means.

5. The method of operating anengine comprising introducing a combustiblecharge of fuel 'and air into a cylinder, compressing and igniting thecharge, releasing some of the charge during the high pressure period ofthe cycle but only when the fuel charge volume introduced into thecylinder is below a predetermined amount, and scavenging exhaust gasfrom the cylinder during the low pressure period of the cycle.

6. In an internal combustion engine, a cylinder having a relief port,avalve-in the port opening away from the interior of the cylinder,pressure means normally urging the valve toward seated position inopposition to pressure in the cylinder, a fuel regulating mechanism, anda connection between the mechanism and the pressure means whereby thepressure means will be regulated in a definite relation with the fueladjustment.

7. In an internal combustion engine, a cylinder having an outlet port, avalve in the port opening away from the interior of the cylinder, springmeans normally urging the valve toward seated position in opposition topressure in the cylinder, operated by the fuel regulating mechanism forvarying the pressure exerted by the spring means against the valve.

8. In an internalcombustion engine, a cylinder having an outlet port, avalve in the port opening away from the interior of the cylinder,pressure means normally urging the valve toward seated position inopposition to pressure in the cylinder, a fuel regulating mechanism, anda connection between the mechanism and the pressure means operable topositively seat the valve when the fuel mechanism is set for maximuminjection.

9. In an internal combustion engine, a cylinder having an outlet port, avalve in the port opening away from the interior of the cylinder,pressure means associated with the valve in a relation opposed to thepressure in the cylinder, a fuel regulating mechanism, and a connectionbetween the pressure means and the mechanism including a cam actuator,said cam adjusting said pressure means during adjustment of said fuelregulating mechanism.

10. In an internal combustion engine, a cylina fuel regulatingmechanism, and means der having an outlet port, a valve in the portopening away from the interior of the cylinder, a

'slidable regulating member, a spring between the valve and theregulating member, an actuator associated to engage the regulator andadjust the compression of the spring, a cam for operating the actuator,a fuel control lever, and a connection between the cam and the fuelcontrol lever, the operation of the fuel control lever, to regulate thefuel, moving said cam to operate the actuator,

11. In a two cycle internal combustion engine, a cylinder, a piston inthe cylinder, said cylinder having inlet and outlet ports thereinadapted to be uncovered when the piston is at one end of its stroke anda relief port adjacent the other end of the piston stroke, a valve inthe relief port, pressure means normally urging the valve toward seatedposition in opposition to pressure in the cylinder, mechanism foradjusting said pressure means whereby negative work can be introducedinto the cylinder during idling of the engine, and fuel control meansconnected to regulate said mechanism.

12. The method of operating an engine comprising introducing unthrottledair charges and liquid fuel charges into a combustion chamber,compressing the air and fuel mixture until combustion occurs, releasingsome of the combustion charge during the high pressure period of thecycle only when the fuel charge in the mixture is below a predeterminedquantity, and scavenging exhaust gas from the cylinder.

, HERBERT C. EDWARDS.

